The invention relates to a bottle stopper, of the type having a first portion adapted to fit the end portion of a bottle neck and attached over a weakened annular region to a tubular security portion to be retained on the neck, the tubular portion being provided on the inside thereof with retaining means adapted to engage at least one protuberance on the bottle neck for such retaining purposes.
When the first portion of the stoppers of the above type is removed, the stopper tears along the annular weakened region, since the tubular security portion is retained on the neck and cannot rise with the first portion. Nevertheless, at the start of removal, the tubular security portion rotates together with the first portion, thus causing a progressive elongation of the plastics material in the tearing portion, forming threads which finally remain attached to the security portion, spoiling its appearance and, therefore that of the bottle itself.
It should also be borne in mind that a majority of wine producers consider it a drawback to stopper bottles with plastic stoppers and prefer the material which may contact the wine to be cork.
Therefore, the problem arises of overcoming the above drawbacks concerning the separation of the security portion and also with respect to the possible use of cork, without this latter meaning having to waive the benefits derived from the use of plastics material.